Free HVAC Contractor Practice Test by State 2026: 3,400+ Questions

The License That Turns a Technician Into a Business Owner

Every building in America needs heating, ventilation, and air conditioning. When the system breaks in a 100-degree Texas summer or a -20-degree Minnesota winter, the HVAC contractor who shows up is not just a repairperson --- they are an essential service provider with a license that took years to earn. In 34 states, you cannot legally install, repair, or service HVAC systems without passing a state contractor licensing exam that tests everything from refrigeration cycles and load calculations to contract law and insurance requirements.

The HVAC contractor exam is one of the most technically demanding trade exams in the construction industry. It covers thermodynamics, refrigerant handling, electrical circuits, ductwork design, hydronic systems, building codes, energy efficiency standards, and state-specific business and law requirements. Most states require both a trade exam and a business/law exam, and many require EPA Section 608 certification as a prerequisite.

The financial rewards match the difficulty. HVAC mechanics and installers earn a median salary of $57,300 per year (BLS, May 2024), with the top 25% earning over $72,020 and master HVAC contractors who run their own businesses earning $80,000-$150,000+. Employment is projected to grow 6% from 2024 to 2034 with about 39,800 openings per year --- driven by new construction, system replacements, and the transition to heat pumps and high-efficiency equipment mandated by updated energy codes.

This guide provides the most comprehensive HVAC contractor exam preparation resource available: state-by-state practice tests, exam format details, domain breakdowns, 10 sample questions with detailed explanations, a structured study plan, and a comparison of free vs. paid resources.

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HVAC Contractor Exam Format at a Glance

Key point: HVAC contractor licensing typically covers heating, ventilation, air conditioning, and refrigeration (HVACR). Many states classify HVAC work under a mechanical contractor license that may also include plumbing or piping work. Verify your state's exact classification to ensure you are studying for the correct exam.

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Free HVAC Contractor Practice Tests by State

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Exam Content Breakdown: What the HVAC Contractor Exam Tests

Domain 1: Refrigeration and Air Conditioning Fundamentals (25-35% of trade exam)

This is the core technical domain and the most heavily weighted section on virtually every state HVAC exam.

• Refrigeration cycle --- The four components (compressor, condenser, metering device, evaporator) and the thermodynamic processes at each stage (compression, condensation, expansion, evaporation). Know the pressure-enthalpy diagram, superheat and subcooling measurement, and what abnormal readings indicate (low charge, overcharge, restriction, compressor failure).

• Refrigerants --- Properties of common refrigerants (R-410A, R-32, R-454B, R-134a, R-404A), including operating pressures, temperature-pressure relationships, GWP (Global Warming Potential), and the AIM Act phase-down schedule. The transition from R-410A to lower-GWP alternatives (R-32, R-454B) is a major 2025-2026 industry change that will appear on updated exams.

• EPA Section 608 --- Universal, Type I, Type II, and Type III certification requirements. Recovery requirements, leak repair requirements (different thresholds for commercial and residential systems), refrigerant sales restrictions, and record-keeping. Many states require EPA 608 certification as a prerequisite for the HVAC license.

• Heat pumps --- Air-source, ground-source (geothermal), and ductless mini-split heat pump systems. Understand reversing valve operation, defrost cycles, auxiliary/emergency heat staging, balance point calculation, and cold-climate heat pump technology. The heat pump market is growing rapidly due to energy code requirements and federal tax incentives.

• System components --- Compressor types (scroll, reciprocating, rotary, variable-speed), condenser types (air-cooled, water-cooled), evaporator types (A-coil, slab), metering devices (TXV, fixed orifice, EEV), and system accessories (accumulators, filter driers, sight glasses, crankcase heaters).

Domain 2: Heating Systems (15-20% of trade exam)

• Gas furnaces --- Natural gas and propane forced-air furnaces: combustion principles, heat exchangers, ignition systems (HSI, direct spark, hot surface), safety controls (limit switches, flame sensors, pressure switches, rollout switches), venting categories (I, II, III, IV), and AFUE ratings. Know how to size a furnace using Manual J load calculations.

• Hydronic heating --- Boiler systems (gas, oil, electric), baseboard radiators, radiant floor heating, expansion tanks, circulating pumps, zone valves, and system controls. Understand the difference between open and closed hydronic systems and proper system fill and air purging procedures.

• Electric heating --- Electric resistance heating elements, heat strips, electric baseboard, and electric boilers. Understand the watt-per-square-foot sizing method and the high operating cost relative to heat pump alternatives.

• Oil heating --- Oil burner components (nozzle, electrodes, pump, primary control), combustion efficiency testing (smoke, CO2, draft, stack temperature), and oil storage tank requirements.

• Combustion analysis --- CO and CO2 measurement, draft testing, combustion air requirements (NFPA 54/International Fuel Gas Code), and carbon monoxide safety standards.

Domain 3: Ductwork and Airflow (10-15% of trade exam)

• Duct design --- Manual D duct design methodology, equal friction vs. static regain vs. velocity reduction methods, duct sizing for branch and trunk lines, and return air sizing. Know how to use a duct calculator or friction chart.

• Airflow measurement --- CFM calculation, air velocity measurement (anemometer, pitot tube), static pressure measurement, and system balancing. Standard delivery is 400 CFM per ton of cooling, with acceptable range of 350-450 CFM/ton.

• Duct materials and installation --- Sheet metal, flexible duct, fiberglass duct board, duct sealing (mastic, tape), insulation requirements (R-values), and support/hanging specifications. Know the maximum allowable length for flex duct runs and when rigid duct is required.

• Air distribution --- Supply register and return grille sizing, throw and spread calculations, diffuser types, and proper placement for mixing and comfort. Understand the effects of undersized returns (high static pressure, reduced airflow, system stress).

Domain 4: Electrical Systems (10-15% of trade exam)

• Basic electrical theory --- Ohm's Law, Watt's Law, series vs. parallel circuits, voltage measurement, amperage measurement, and resistance measurement. Know how to use a multimeter and a clamp meter.

• HVAC electrical components --- Contactors, relays, capacitors (start and run), transformers, thermostats (conventional and communicating), motor types (PSC, ECM, variable-speed), and safety switches. Know how to diagnose common failures using electrical measurements.

• Wiring and circuits --- Wire sizing (NEC ampacity tables), circuit breaker sizing, disconnect requirements, proper grounding, and low-voltage control wiring. Understand the relationship between MCA (minimum circuit ampacity) and MOP (maximum overcurrent protection) on equipment nameplates.

• Control systems --- Thermostat wiring (R, G, Y, W, C, O/B), zoning systems, building automation basics, and communicating system protocols. The shift toward smart thermostats, communicating systems, and IoT-connected equipment is accelerating.

Domain 5: Codes, Standards, and Load Calculations (10-15% of trade exam)

• Manual J load calculations --- Residential heating and cooling load calculations per ACCA Manual J. Know the inputs (building envelope, windows, infiltration, internal gains, climate data) and how oversizing or undersizing affects comfort, efficiency, and equipment life.

• Mechanical codes --- International Mechanical Code (IMC), Uniform Mechanical Code (UMC), NFPA 90A and 90B, and state amendments. Know combustion air requirements, clearance to combustibles, vent sizing, and equipment installation requirements.

• Energy codes --- IECC (International Energy Conservation Code), ASHRAE 90.1 for commercial, and state energy codes. Minimum efficiency requirements (SEER2, EER2, HSPF2, AFUE) and the 2023 DOE efficiency standard updates that took effect January 1, 2023.

• Refrigerant regulations --- EPA Section 608, AIM Act, state-specific refrigerant management rules, and ASHRAE 15 and 34 refrigerant safety standards.

Domain 6: Business and Law (entire business exam, or 20-30% of combined exam)

• Contractor licensing law --- State-specific licensing requirements, classifications, financial responsibility requirements, and penalties for unlicensed contracting.

• Contract and lien law --- Contract elements, change order procedures, breach remedies, mechanic's lien rights and procedures, bond claims, and the statute of limitations for construction defect claims.

• Insurance and bonding --- General liability, workers' compensation, commercial auto, contractor bonds (license, performance, payment), and minimum coverage requirements.

• Employee management --- Workers' compensation, OSHA compliance, employee classification (W-2 vs. 1099), payroll requirements, and anti-discrimination laws.

• Permits and inspections --- When mechanical permits are required, inspection procedures, code compliance, and the relationship between the contractor and the authority having jurisdiction (AHJ).

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10 HVAC Contractor Sample Questions with Answers

Question 1: A residential air conditioning system is running but not cooling adequately. The suction line is warm, suction pressure is low, and superheat is high. What is the most likely cause?

Answer: Low refrigerant charge. Low suction pressure combined with high superheat and a warm suction line indicates the evaporator is starved for refrigerant --- there is not enough liquid refrigerant entering the evaporator to absorb heat effectively. The high superheat confirms the refrigerant is fully evaporated before reaching the suction line, leaving excess heat in the vapor. Check for leaks before adding charge. Per EPA Section 608, systems with a charge over 50 pounds must be repaired if the leak rate exceeds the applicable threshold (currently 10% for commercial refrigeration, 20% for comfort cooling and commercial AC).

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Question 2: You are sizing a furnace for a home with a Manual J heating load of 60,000 BTU/h. The available furnace options are 60,000, 80,000, and 100,000 BTU/h input. Which do you select if the furnace has a 96% AFUE rating?

Answer: The 80,000 BTU/h input furnace. At 96% AFUE, the output is 80,000 x 0.96 = 76,800 BTU/h, which covers the 60,000 BTU/h load with appropriate margin. The 60,000 BTU/h input furnace would produce only 57,600 BTU/h output --- insufficient for the load. The 100,000 BTU/h furnace would produce 96,000 BTU/h output, which is 60% oversized and would cause short cycling, poor humidity control, and accelerated wear. Proper sizing is within 100-125% of the Manual J calculated load.

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Question 3: What is the standard airflow rate per ton of cooling for a residential split-system air conditioner?

Answer: 400 CFM per ton, with an acceptable range of 350-450 CFM per ton. A 3-ton system should deliver approximately 1,200 CFM. Airflow below 350 CFM/ton can cause the evaporator coil to freeze (the coil temperature drops below 32 degrees F), reducing capacity and potentially damaging the compressor with liquid slugging. Airflow above 450 CFM/ton reduces the coil's ability to dehumidify, resulting in cold but clammy air. Measure static pressure across the system to verify adequate airflow --- total external static pressure should not exceed the equipment manufacturer's maximum (typically 0.5 inches water column).

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Question 4: An EPA Section 608 certified technician recovers R-410A from a residential system before major repair. What is the minimum recovery efficiency required?

Answer: For systems containing more than 200 pounds of refrigerant, recovery to 0 psig is required. For systems containing less than 200 pounds (most residential), recovery must achieve 0 psig if the recovery equipment was manufactured before November 15, 1993, or 90% of the charge if manufactured after that date (for systems with an operating charge of more than 200 pounds, 90% is required regardless). In practical terms, for residential R-410A systems, recover as much refrigerant as possible using approved recovery equipment, verify with a pressure gauge, and record the amount recovered. Venting refrigerant is illegal under Section 608 with fines up to $44,539 per day per violation.

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Question 5: A homeowner complains that their two-story home is too hot upstairs and too cold downstairs in summer. The single-zone HVAC system is properly sized. What is the most likely issue and solution?

Answer: Inadequate air balancing and/or insufficient return air upstairs. Hot air rises, so upper floors naturally require more cooling capacity. Solutions include: (1) partially close supply dampers to downstairs zones and fully open upstairs dampers to redirect airflow; (2) add return air pathways upstairs (transfer grilles, jump ducts, or additional return ducts) to pull warm air from upper levels; (3) install a zoning system with motorized dampers and a zone control board to independently control upstairs and downstairs temperatures; (4) verify duct runs to the second floor are properly insulated and sealed, as attic duct runs are subject to extreme heat gain. A zoning system is the most effective long-term solution.

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Question 6: What is the difference between SEER and SEER2, and why does it matter for the 2026 exam?

Answer: SEER (Seasonal Energy Efficiency Ratio) and SEER2 both measure cooling efficiency, but SEER2 uses a higher external static pressure (0.5 inches WC instead of 0.1-0.3 inches WC) to simulate real-world duct system conditions. SEER2 ratings are lower than SEER ratings for the same equipment --- approximately 4.7% lower. As of January 1, 2023, all new residential AC and heat pump equipment must meet DOE minimum efficiency standards using the SEER2 metric: 14.3 SEER2 in the Northern region and 15.0 SEER2 in the Southern region (the equivalent of the old 15 SEER). Understanding SEER2 is essential because your exam will reference current efficiency standards.

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Question 7: A gas furnace cycles on and off repeatedly (short cycling) and the LED diagnostic code indicates a limit switch trip. What is the most likely cause?

Answer: Restricted airflow causing the heat exchanger to overheat and trigger the high-limit switch. The most common causes are: (1) dirty or clogged air filter (check and replace first); (2) closed or blocked supply registers; (3) undersized or collapsed ductwork; (4) failed blower motor or blower capacitor (motor not running at full speed); (5) dirty evaporator coil blocking airflow. The limit switch is a safety device that shuts off the gas valve when the heat exchanger temperature exceeds the setpoint (typically 150-200 degrees F). After the heat exchanger cools, the limit switch resets and the furnace fires again, creating the short-cycling pattern. Address the root cause --- never bypass a limit switch.

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Question 8: You are installing a new gas furnace in a residential basement. What are the combustion air requirements?

Answer: Per the International Fuel Gas Code (IFGC) and NFPA 54, a gas furnace in a confined space (less than 50 cubic feet per 1,000 BTU/h of total input rating of all appliances) requires combustion air from outdoors. Two openings are required: one within 12 inches of the top of the enclosure and one within 12 inches of the bottom. For vertical ducts, each opening must provide 1 square inch per 4,000 BTU/h of total input. For horizontal ducts, each opening must provide 1 square inch per 2,000 BTU/h. If the room qualifies as an unconfined space (50 or more cubic feet per 1,000 BTU/h), combustion air can come from the building interior, but the building must have adequate infiltration. High-efficiency condensing furnaces (Category IV) use sealed combustion with dedicated intake pipes, which eliminates the room air requirements.

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Question 9: A subcontractor installs ductwork on your HVAC project but you have not paid them. They threaten to file a mechanic's lien. What are your obligations?

Answer: The subcontractor has a legal right to file a mechanic's lien against the property if they have performed work and not been paid, provided they have complied with state-specific preliminary notice requirements. As the general contractor, you are contractually obligated to pay the subcontractor per your agreement. If the lien is filed, the property owner may withhold payment from you or require you to bond off the lien. To prevent liens from subcontractors, use conditional lien waivers with each progress payment --- the sub waives lien rights for the amount received. Lien filing deadlines, preliminary notice requirements, and enforcement procedures are highly state-specific and are among the most tested business/law topics.

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Question 10: You measure the suction pressure of an R-410A system at 118 psig and the suction line temperature at 55 degrees F. What is the superheat, and is it normal?

Answer: At 118 psig, the saturation temperature for R-410A is approximately 40 degrees F (use a P-T chart or digital gauge). Superheat = actual suction line temperature minus saturation temperature = 55 - 40 = 15 degrees F. A superheat of 15 degrees F is within the normal range for a TXV (thermostatic expansion valve) system, which typically targets 8-14 degrees F of superheat but can operate normally in the 5-20 degrees F range depending on conditions. For a fixed-orifice system, target superheat varies with indoor and outdoor conditions (use the manufacturer's superheat charging chart). Excessively high superheat (above 25 degrees F) indicates low charge or restricted metering device. Excessively low superheat (below 5 degrees F) indicates overcharge or wide-open metering device, risking liquid flood-back to the compressor.

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How to Prepare: 8-Week HVAC Contractor Exam Study Plan

Week 1: Refrigeration Cycle and System Fundamentals

• Study the four components of the refrigeration cycle and thermodynamic principles at each stage
• Learn pressure-temperature relationships for common refrigerants (R-410A, R-32, R-134a)
• Master superheat and subcooling measurement and interpretation
• Begin taking 20 practice questions daily on OpenExamPrep

Week 2: Air Conditioning and Heat Pump Systems

• Study split-system and packaged AC system components and operation
• Learn heat pump operation: reversing valve, defrost, auxiliary heat, balance point
• Review ductless mini-split and variable refrigerant flow (VRF) systems
• Study the SEER2/EER2/HSPF2 efficiency metrics and DOE minimum standards
• Increase to 30 practice questions daily

Week 3: Heating Systems

• Study gas furnace operation, safety controls, and diagnostic procedures
• Review hydronic heating systems: boilers, radiant floor, baseboard
• Study combustion analysis, venting categories, and combustion air requirements
• Review oil heating fundamentals and electric heating systems
• Take 30 practice questions daily

Week 4: Ductwork, Airflow, and Electrical

• Study Manual D duct design and duct sizing methods
• Learn airflow measurement techniques and system balancing
• Review electrical theory: Ohm's Law, circuits, motor types, capacitors, contactors
• Study thermostat wiring, control systems, and zoning
• Take 35 practice questions daily

Week 5: Codes, Standards, and Load Calculations

• Study Manual J residential load calculation methodology
• Review IMC/UMC mechanical codes and state-specific amendments
• Study EPA Section 608 requirements and refrigerant regulations
• Review energy codes (IECC, ASHRAE 90.1) and minimum efficiency standards
• Take 35 practice questions daily

Week 6: Business and Law

• Study your state's contractor licensing law in detail
• Review mechanic's lien law: preliminary notice, filing deadlines, enforcement
• Study contract law: elements, change orders, breach, dispute resolution
• Review insurance requirements: GL, workers' comp, bonding
• Take 40 practice questions daily

Week 7: Safety, Permits, and Estimating

• Study OSHA safety requirements for HVAC work
• Review permit requirements and inspection procedures
• Study estimating methods: material takeoff, labor calculations, markup
• Review employee management: hiring, classification, payroll
• Take 40 practice questions daily under timed conditions

Week 8: Full-Length Practice Exams and Final Review

• Take 3-4 full-length practice exams simulating test conditions
• Review every missed question and identify knowledge gaps
• Re-study refrigeration fundamentals and business/law --- the two highest-weighted sections
• Focus final two days on your weakest areas
• Schedule your exam for end of Week 8

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8 Study Tips for the HVAC Contractor Exam

1. Master the refrigeration cycle --- This is the foundation of every HVAC exam. If you can diagnose a system from pressure and temperature readings (superheat, subcooling, saturation), you can answer 30%+ of the trade exam. Practice with P-T charts until the relationships are automatic.

2. Know Manual J and Manual D --- Load calculation and duct design questions appear on every exam. Understand the inputs, the methodology, and the consequences of oversizing and undersizing. You do not need to memorize tables, but you need to understand the process.

3. Study EPA 608 thoroughly --- Many states require EPA 608 certification as a prerequisite, and refrigerant regulations appear on the state exam regardless. Know recovery requirements, leak repair thresholds, venting prohibitions, and the AIM Act phase-down schedule.

4. Learn the current efficiency standards --- The transition to SEER2/EER2/HSPF2 and the regional efficiency requirements (Northern vs. Southern) are current and testable. Know the minimum standards and when they took effect.

5. Know your state's lien law --- Mechanic's lien questions are among the most missed on the business exam. Memorize preliminary notice requirements, filing deadlines, and enforcement procedures for your state.

6. Study with the code books your state references --- If your exam is open-book, tab and bookmark your IMC/UMC, NEC, and state code books. Practice finding specific provisions under time pressure. If closed-book, memorize key code requirements.

7. Understand the heat pump transition --- Heat pump technology is the future of the HVAC industry. Variable-speed compressors, cold-climate heat pumps, and the shift away from fossil fuel heating are major trends that appear on updated exams.

8. Practice electrical troubleshooting --- Ohm's Law, capacitor testing, contactor diagnosis, and motor amp draw calculations are foundational. These are not difficult if practiced but are commonly missed by candidates who focused only on refrigeration.

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Free vs. Paid HVAC Contractor Prep Resources

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Why OpenExamPrep for HVAC Contractor Exam Prep

• Completely free --- no signup, no credit card, no trial period that expires
• 3,400+ state-specific questions covering refrigeration, heating, ductwork, electrical, codes, and business/law for all 34 states
• All 34 states covered --- find your state's practice test in the table above
• AI-powered tutor that explains thermodynamics, electrical theory, code requirements, and legal concepts
• Updated for 2026 --- reflects SEER2 standards, AIM Act refrigerant phase-down, and the latest state licensing requirements
• Instant access --- start practicing right now from any device
• Detailed explanations --- every question includes the technical rationale and references applicable codes or standards

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Frequently Asked Questions